rq-scheduler 0.3.1

Scheduling a Job

There are two ways you can schedule a job. The first is using RQ Scheduler’s enqueue_at:

from rq import use_connection
from rq_scheduler import Scheduler
from datetime import datetime

use_connection() # Use RQ's default Redis connection
scheduler = Scheduler() # Get a scheduler for the "default" queue

# Puts a job into the scheduler. The API is similar to RQ except that it
# takes a datetime object as first argument. So for example to schedule a
# job to run on Jan 1st 2020 we do:
scheduler.enqueue_at(datetime(2020, 1, 1), func)

# Here's another example scheduling a job to run at a specific date and time,
# complete with args and kwargs
scheduler.enqueue_at(datetime(2020, 1, 1, 3, 4), func, foo, bar=baz)

The second way is using enqueue_in. Instead of taking a datetime object, this method expects a timedelta and schedules the job to run at X seconds/minutes/hours/days/weeks later. For example, if we want to monitor how popular a tweet is a few times during the course of the day, we could do something like:

from datetime import timedelta

# Schedule a job to run 10 minutes, 1 hour and 1 day later
scheduler.enqueue_in(timedelta(minutes=10), count_retweets, tweet_id)
scheduler.enqueue_in(timedelta(hours=1), count_retweets, tweet_id)
scheduler.enqueue_in(timedelta(days=1), count_retweets, tweet_id)

You can also explicitly pass in connection to use a different Redis server:

from redis import Redis
from rq_scheduler import Scheduler
from datetime import datetime

scheduler = Scheduler('default', connection=Redis('192.168.1.3', port=123))
scheduler.enqueue_at(datetime(2020, 01, 01, 1, 1), func)

Periodic & Repeated Jobs

As of version 0.3, RQ Scheduler also supports creating periodic and repeated jobs. You can do this via the enqueue method. This is the syntax:

scheduler.enqueue(
    scheduled_time=datetime.now(), # Time for first execution
    func=func,                     # Function to be queued
    args=[arg1, arg2],             # Arguments passed into function when executed
    kwargs = {'foo': 'bar'},       # Keyword arguments passed into function when executed
    interval=60,                   # Time before the function is called again, in seconds
    repeat=10                      # Repeat this number of times (None means repeat forever)
)

Canceling a job

To cancel a job, simply do:

scheduler.cancel(job)

Running the scheduler

RQ Scheduler comes with a script rqscheduler that runs a scheduler process that polls Redis once every minute and move scheduled jobs to the relevant queues when they need to be executed:

# This runs a scheduler process using the default Redis connection
rqscheduler

If you want to use a different Redis server you could also do:

rqscheduler --host localhost --port 6379 --db 0

The script accepts these arguments:

• -H or --host: Redis server to connect to

• -p or --port: port to connect to

• -d or --db: Redis db to use

• -P or --password: password to connect to Redis